Windows machine periodically crashes network

I have an Ubuntu Noble/24.04 server managing my network. It runs DHCP, DNS, and samba. Several Linux machines and one Windows machine are connected to it via a gig switch. The machines on the switch get access to the rest of the world through packet forwarding on the Linux server. In other words, I run my own router. Periodically, the network just goes down. None of the machines can talk to each other. Power cycling the switch doesn't help. Restarting network services on the Linux box doesn't help. I even tried unloading the kernel driver for the ethernet card on the Linux box and reloading it. # rmmod e1000e # insmod e1000e No joy. The only thing that seems to work is rebooting the Linux box. I was beating my head against the wall for weeks. Bought a new switch, did everything I could think of. Then, just to keep the Windows machine from being effected, I connected it directly to a port on the router supplied by my ISP, AT&T. Then the AT&T router started going down. My own network was uneffected. I had to power cycle the AT&T router to fix it. I put the Windows machine back on my own network and the problem began again. So now I know that this Windows machine is doing something to the network to make a router freeze. How is that even possible? If it is static or something, why wouldn't that effect the switch instead? Whatever is happening has to go from the Windows machine, through the switch, to the Linux server, and effect it in such a way so that even reloading the kernel module for the network card doesn't fix the problem. Anybody got an explanation for that? Any ideas at all? PS: If you are wondering why I am essentially building my own router instead of just connecting everybody directly to the AT&T router, it's because this setup is left over from the days of dial-up modems. At one time, we had a Linux box with a 56K modem providing a network connection we all shared. Anyone old enough to remember those days, someone would be on-line and someone else would fire up their modem to get on-line. That would disconnect the first person. So this was our solution. In fact, it was a beautiful thing for years before ISPs started providing smart routers. And now its so ingrained into our systems it is difficult to get rid of.

Greetings, What happens when you just unplug the NIC when this is happening from the Windows machine? Thanks and 73, Billy L. Irwin – K9oh Assistant Section Manager – SKYWARN Program Manager ARRL – South Carolina Section Phone: 803-497-5560 -----Original Message----- From: John G. Heim via Blind-sysadmins <blind-sysadmins@lists.hodgsonfamily.org> Sent: Wednesday, January 15, 2025 2:08 PM To: Mailing list for blind system administrators <blind-sysadmins@lists.hodgsonfamily.org> Cc: John G. Heim <jheim@math.wisc.edu> Subject: [Blind-sysadmins] Windows machine periodically crashes network I have an Ubuntu Noble/24.04 server managing my network. It runs DHCP, DNS, and samba. Several Linux machines and one Windows machine are connected to it via a gig switch. The machines on the switch get access to the rest of the world through packet forwarding on the Linux server. In other words, I run my own router. Periodically, the network just goes down. None of the machines can talk to each other. Power cycling the switch doesn't help. Restarting network services on the Linux box doesn't help. I even tried unloading the kernel driver for the ethernet card on the Linux box and reloading it. # rmmod e1000e # insmod e1000e No joy. The only thing that seems to work is rebooting the Linux box. I was beating my head against the wall for weeks. Bought a new switch, did everything I could think of. Then, just to keep the Windows machine from being effected, I connected it directly to a port on the router supplied by my ISP, AT&T. Then the AT&T router started going down. My own network was uneffected. I had to power cycle the AT&T router to fix it. I put the Windows machine back on my own network and the problem began again. So now I know that this Windows machine is doing something to the network to make a router freeze. How is that even possible? If it is static or something, why wouldn't that effect the switch instead? Whatever is happening has to go from the Windows machine, through the switch, to the Linux server, and effect it in such a way so that even reloading the kernel module for the network card doesn't fix the problem. Anybody got an explanation for that? Any ideas at all? PS: If you are wondering why I am essentially building my own router instead of just connecting everybody directly to the AT&T router, it's because this setup is left over from the days of dial-up modems. At one time, we had a Linux box with a 56K modem providing a network connection we all shared. Anyone old enough to remember those days, someone would be on-line and someone else would fire up their modem to get on-line. That would disconnect the first person. So this was our solution. In fact, it was a beautiful thing for years before ISPs started providing smart routers. And now its so ingrained into our systems it is difficult to get rid of. _______________________________________________ Blind-sysadmins mailing list -- blind-sysadmins@lists.hodgsonfamily.org To unsubscribe send an email to blind-sysadmins-leave@lists.hodgsonfamily.org

Hmm, I cannot recall ever simply unplugging the cable to the Windows machine. I probably did that because I tried swapping out cables. But I do know that power cycling the switch does nothing. On 1/15/25 1:28 PM, Billy Irwin via Blind-sysadmins wrote:
Greetings,
What happens when you just unplug the NIC when this is happening from the Windows machine?
Thanks and 73,
Billy L. Irwin – K9oh Assistant Section Manager – SKYWARN Program Manager ARRL – South Carolina Section Phone: 803-497-5560
-----Original Message----- From: John G. Heim via Blind-sysadmins <blind-sysadmins@lists.hodgsonfamily.org> Sent: Wednesday, January 15, 2025 2:08 PM To: Mailing list for blind system administrators <blind-sysadmins@lists.hodgsonfamily.org> Cc: John G. Heim <jheim@math.wisc.edu> Subject: [Blind-sysadmins] Windows machine periodically crashes network
I have an Ubuntu Noble/24.04 server managing my network. It runs DHCP, DNS, and samba. Several Linux machines and one Windows machine are connected to it via a gig switch. The machines on the switch get access to the rest of the world through packet forwarding on the Linux server. In other words, I run my own router.
Periodically, the network just goes down. None of the machines can talk to each other. Power cycling the switch doesn't help. Restarting network services on the Linux box doesn't help. I even tried unloading the kernel driver for the ethernet card on the Linux box and reloading it.
# rmmod e1000e
# insmod e1000e
No joy. The only thing that seems to work is rebooting the Linux box. I was beating my head against the wall for weeks. Bought a new switch, did everything I could think of. Then, just to keep the Windows machine from being effected, I connected it directly to a port on the router supplied by my ISP, AT&T. Then the AT&T router started going down. My own network was uneffected. I had to power cycle the AT&T router to fix it. I put the Windows machine back on my own network and the problem began again.
So now I know that this Windows machine is doing something to the network to make a router freeze. How is that even possible? If it is static or something, why wouldn't that effect the switch instead? Whatever is happening has to go from the Windows machine, through the switch, to the Linux server, and effect it in such a way so that even reloading the kernel module for the network card doesn't fix the problem.
Anybody got an explanation for that? Any ideas at all?
PS: If you are wondering why I am essentially building my own router instead of just connecting everybody directly to the AT&T router, it's because this setup is left over from the days of dial-up modems. At one time, we had a Linux box with a 56K modem providing a network connection we all shared. Anyone old enough to remember those days, someone would be on-line and someone else would fire up their modem to get on-line. That would disconnect the first person. So this was our solution. In fact, it was a beautiful thing for years before ISPs started providing smart routers. And now its so ingrained into our systems it is difficult to get rid of.
_______________________________________________ Blind-sysadmins mailing list -- blind-sysadmins@lists.hodgsonfamily.org To unsubscribe send an email to blind-sysadmins-leave@lists.hodgsonfamily.org _______________________________________________ Blind-sysadmins mailing list -- blind-sysadmins@lists.hodgsonfamily.org To unsubscribe send an email to blind-sysadmins-leave@lists.hodgsonfamily.org
participants (2)
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Billy Irwin
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John G. Heim